Tertiary diamides

ABSTRACT

This invention relates to novel liquid tertiary diamides having the following structural formula:   WHEREIN N O-10 R -(CH2)m-CH3 wherein M 4-12 One such diamide is N,N&#39;&#39;-2,2,5,5-tetramethylhexamethylene-N,N&#39;&#39;dimethylpelargonamide. The diamides have utility as heat transfer fluids and plasticizers.

United States Patent [191 Thompson [451 June 10, 1975 TERTIARY DIAMIDES [75] Inventor: Robert M. Thompson, Chalfonte,

Del.

221 Filed: Oct. 2, 1972 21 Appl. No.: 293,979

[52] US. Cl. 260/4045; 252/73; 260/29.1;

[51] Int. Cl. C07c 103/00 [58] Field of Search 260/4045, 561 R [56] References Cited UNITED STATES PATENTS 2,132,388 10/1938 Berchet 260/4045 X 2,632,023 3/1953 Bortnick 260/561 R 3,262,913 7/1966 Chiba et al 260/561 R 3,539,629 11/1970 Mackellar 260/561 R FOREIGN PATENTS OR APPLICATIONS 903,200 8/1962 United Kingdom 260/561 R OTHER PUBLICATIONS DeCoste, Chem. Abstracts, 72:13299r.

Primary ExaminerLewis Gotts Assistant ExaminerEthel G. Love Attorney, Agent, or FirmGeorge L. Church; .1. Edward Hess; Anthony Potts, Jr.

[57] ABSTRACT This invention relates to novel liquid tertiary diamides having the following structural formula:

One such diamide is N,N'-2,2,5,S-tetramethylhexamethylene-N,Ndimethylpelargonamide. The diamides have utility as heat transfer fluids and plasticizers.

3 Claims, No Drawings TERTIARY DIAMIDES C ROSS-REFERENCES TO RELATED APPLICATIONS This invention is related to those described in the following listed applications:

Serial Numbers Inventors 293,980 R. M Thompson 293,981 R. M Thompson 293,982 R. M Thompson 293,984 R. M. Thompson and F. E. Didot 293,983 R. M. Thompson and A. F. Talbot All of the aforementioned applications filed the same date as this application. The first of the aforementioned applications relates to another class of diamides; the second and third relate to the use of certain diamides as lubricants; the fourth to the use of certain diamides as swelling agents and the last one to the use of certain diamides as a component of greases.

SUMMARY OF THE INVENTION This invention pertains to novel tertiary diamides having the following structural formula:

tetramethylhexamethylene-N,N-dimethylpelargona mide. The diamides have utility as heat transfer fluids and plasticizers.

DESCRIPTION OF THE INVENTION The novel tertiary diamides of this invention can be prepared by the methylation of a sodium salt of a suitable diamide by using, for example, methyliodide. This general reaction is illustrated by the following equatron:

on on n n 3 3 n 11 R-C-N-C-C-(Cll -c- C-N-C-R Na cu I II I I 2 n I II 3 0 11 C113 cu o (1) \i CH cu ca cu 3 3 3 H 3 0 CH CH 0 6 Other'bases besides sodium can be used and other methylhalides besides methyliodide can be used. The R appearing in equation (1) equals (CI-I ),,,--CH

whereas m 4-12, preferably, 5-10 and the n equals 0-10, preferably, 1-8.

Precursors of the suitable diamide of equation (1) can be prepared by reacting suitable diamines with saturated aliphatic monoacids. This general reaction is illustrated by the following equation:

- CH -C -ii- -I T CH3 Cil The R of the saturated aliphatic nonacid of equation 1 equals -(CI-I ),,,Cl-I wherein m 4-12, preferably, 5-10 while the n of the diamine equals 0-10, preferably, 1-8.

Precursors of the suitable diamines of equation (2) can be prepared by hydrogenating a suitable nitrile. A suitable nitrile is a paraffinic aliphatic material having two methyl radicals attached to each of the two [3 carbons. This general reaction is illustrated by the following equation:

(3) I Cii. cu-

The n of the nitrile of equation (3) equals 0-10, preferably, 1-s. i

The precursors of the nitriles of equation (3) can be prepared by interaction of a suitable paraffinic dihalide with sodium or potassium cyanide in aqueous-alcoholic solution, thus (4) XR'X -l- 2KCN N E CR'C=N 21(X The R' of the paraffinic halide equals CIl 3 9 -3 43 Ch CH 3 on 3 wherein n equals 0-10, preferably, 1-8.

Particular nitriles can be prepared by other methods than that shown by equation (4). For example, 2,2,5,5- tetramethylhexamethylene dinitrile can be prepared by the free radical coupling of pivalonitrile a)a E The tertiary diamides of present invention have many 5 properties which make them excellent heat transfer media. Among these properties are that they are generally innocuous towards metals, have relatively good thermal stability, have high boiling points and are liquid at ambient temperature. A comprehensive discussion.

of heat-transfer media otherthan water is given in Kirk- Othmer, ENCYCLOPEDIA OF CHEMICAL TECH- NOLOGY, second Edition, Volume 10. Also, because of their high boiling points the tetiary diamines have utility as a plasticizer. The latter is generally an organic compound added to some solid polymers both to facilitate processing and to increase the flexibility and toughness of the final product by internal modification of the polymer molecule.

Following is an example of how a tertiary diamide of present invention was prepared; also reported is its physical properties.

EXAMPLE a. Preparation of the dinitrile milliliters of water. During the simultaneous addition,v

which required some minutes, the agitated mixture was maintained at a temperature of 30C. by means of an ice-bath. Afterwards, the solid dinitrile was removed from the mixture by.filtration. The removed solid dinitrile was water washed and dried. The dried dinitrile was recrystallized from 180 milliliters of ethyl alcohol. The recrystallized 01,01,01',a'-tetramethyladiponitrile had a melting point of 137-l38C.

b. Preparation of the diamine 50 grams of the aforementioned dinitrile were charged to a 1 liter bomb along with 500 milliliters of methanol and 5 grams of Raney nickel. Also, the bomb was pressurized with hydrogen to a pressure of 1,200 psig. The bomb with its contents was heated to a temperature of 60C. and rocked for 8.5 hours. Then, after the temperature of the bomb reached ambient temperature, the bomb was opened and the reaction mixture remmoved. The latter was filtered to remove the Raney nickel and subsequently, the methanol evaporated. The remaining viscous oil was distilled. Its boiling point was 60C. at 4mm Hg. The measured nitrogen content of the 2,2,5,5-tetramethylhexamethylene diamine was 15.9 weight percent compared to 16.3 weight percent calculated for C H N 0. Preparation of the pelargonamide Th'e resultin'g' mixture in the flask was heated to a temperatu're of l80-190C., with stirring, and'maintained at that temperature until no more water, a reaction product, came over into the Dean Stark trap.

Afterwards, the heating was stopped, the flask and its contents were allowed to cool. After cooling, 150 millid. Methylation of the pelargonamide 800 milliliters of sodium dried xylene were charged to a 2 liter reaction flask equipped with stirrer, reflux condenser and nitrogen inlet. The xylene had been just recently distilled to remove impurities. Also, to the reaction flask were charged 3.5 grams of sodium and 33 grams of the aforementioned pelargonamide. The resulting mixture in the flask was agitated and refluxed overnight under a nitrogen atmosphere.

After refluxing overnight, the three component mixture was transferred under nitrogen to a dry one liter flask equipped with a cold finger condenser, magnetic stirrer and nitrogen inlet. The cold finger condenser contained a dry ice-acetone mixture. The flask was heated to a temperature of 40C. and while maintained at that temperature, 17.7 grams of methyl iodide were added to the agitated mixture dropwise. The dropwise addition was completed in an hour, but the agitation at room temperature, continued for about 20 hours. The flask and its contents were allowed to cool; afterwards the mixture was filtered to remove the precipitated sodium iodide. The filtered solution was water washed and the xylene solvent removed by distillation. Infrared examination of the resulting 25 grams of liquid indicated the presence of NH bands and therefore, that the reaction was incomplete.

The aforementioned procedure for the methylation of the pelargonamide (step d) was repeated. After this second treatment, the amide liquid, as indicated by infrared examinatiomwas free of NH bands. The color of the resulting tetramethylhexamethylene-N,N'-dimethylpelargonamide was slightly yellow. The yellow tint was believed to be from trace impurities.

The invention claimed is:

2. Compound according to claim 1 wherein n l-8 and m 5-l0.

3. Compound according to claim 2 wherein the diamide is N,N'-2,2,5,5-tetramethylhexamethylene-N,N'-

dimethylpelargonamide.

N,N '-dimethyl-2,2,5 ,5- 

2. Compound according to claim 1 wherein n 1-8 and m 5-10.
 3. Compound according to claim 2 wherein the diamide is N,N''-2, 2,5,5-tetramethylhexamethylene-N,N''-dimethylpelargonamide. 